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Discussion Starter #1
Ok guys just got a new pro 40 dually and am trying to paper tune. What nock hieght do I need to use to get rid of a low left tear? I am using a tt rest and getting good clearence but can not get rid of a low tear! I though with a 2 cam bow the nock hieght should be about level but I am almost 1/8" high now. Cams are rolling over even. Center shot is at least 13/16 if not 7/8 from riser is that right it looks like it is when looking from the back. I am using a Dloop only right now do I need to change to tied nock with dloop aroung it? or below it?
 

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soemtimes it takes just a half twist or one twist of one cable or the other to get it exact and fly like you want. Also you might have the TT dropping to early, contary to what some people believe it needs to travel at least 3-4 inches at the minimum before dropping.
 

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Discussion Starter #3
Strodr one twist to get what right? I have the cams hitting the wal at the same time already. But my rest could be dropping eary I think it only comes up about the last 1 1/2"- 2".
 

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A low tear on a two cam bow is sometimes indicative of a cam timing issue. It would appear that the bottom cam is advanced towards the target a slight amount. This leaves the top cam returning slightly behind the bottom upon release. To correct, simply shorten the split cable attached to the top cam, starting in half turns or full turns until the problem is corrected. What is happening is that because the bottom cam is "advanced", the nocking point travels downwards as the bow is released. By advancing the top cam towards the target, we are able to straighten out the nocking point path to achieve an acceptable tear through paper(IMHO bullet hole to within 3/16"" nock high), and consequently achieve perfect arrow flight with broadheads. Make sure to twist cable so you are tightening the servings and shortening at the same time. If you wish to double check your results, try a "creep tune" test. This is reprinted from GRIV on an earlier thread. Good luck!

The Creep Tune procedure is as follows:

1. Set the timing as close as you can by eye (you don't have put a micrometer on it; just get as close as you can)

2. Sight your bow in at twenty yards.

3. Put a piece of masking tape on your target butt horizontally. In a pinch, you can use the top edge of a target face.

4. Pull your bow into the wall as hard as you can and shoot arrow #1 at the tape.

On the next shot, creep forward to the front of the valley and shoot arrow #2 at the tape. You make need to re-shoot these shots a couple of times to rule out bad shots.

5. If your bow is in perfect time, both arrows will hit the tape or they will land on the same horizontal plane. (Level with the tape or on the tape)

If the "creep" shot hits HIGH, TIGHTEN or SHORTEN the cable that connects to the BOTTOM cam.
If the "creep" shot hits LOW, TIGHTEN or SHORTEN the cable that connects to the TOP cam.

Make very small, one or two turn, adjustments a time. A little twist goes a long way. You can fine-tune your timing by repeating the test at forty yards. If you make an adjustment at this distance do not turn your cable more that a half a turn at a time. Too much adjustment at this distance can send an arrow over the target butt or in the dirt. When you have completed the test, your bow will be in perfect time, and given that your other accessories are adjusted properly, your bow is as accurate as it can possibly be.
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Discussion Starter #5
So Jim do you just not worry about a paper tear untill you creep tune? Seems to me when you are creep tuning you will get the cams out of time to hit the wall at the same time? Sorry for all the questions Just trying to understand.
 

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Actually, you might find that both methods, if done correctly, will yied the same results. I would start with the paper tuning first. Proceed to the creep test after first shooting a few groups, paying particular attention to how the bow reacts during and after the shot. Now that you have a starting point, remember to only change one variable at a time so you can track modifications. Before you know it, you'll be crashing arrows together.
 

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Discussion Starter #7
Ok here we go again. Jim I tried to do what you said but it threw the timing off again. Ha HA by the time I got through getting it back in time with both cams hitting the wall at the same time the bottom cam and the top cam are about 1/16 of an inch different at rest. Is this normal or do I go back and get them close at rest and start over on trying to get them to hit the wall at the same time?
 

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A left tear that you can't get rid of is usually due to a weak spine on your arrow. I have to shoot a stiffer arrow then what the chart calls for with my Patriot DC. Try that first. I'm shooting ACC 3/49 with my #60 Patriot. Anything lighter and I start getting the left tear. You may be a little low on the nock point too. I like to bare shaft tune to set that.
 

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The rest position of the cams really doesn't tell us a whole lot. The best way to check timing is at full draw. Once you have the cams touching the wall at the same time, it is time to try paper tuning and then creep tuning. After you have the desired paper tune and creep tune, leave it alone and just shoot it. It only takes a minute difference in cam rotation to effect a major difference in arrow flight in such an aggressive cam. Did you paper tune again after advancing the top cam?
 

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Very interested

I have a pro38 duelcam that has a consistant 1 1/2 " nock low tear that Ican't get rid of so keep us posted on this thread. At 10 yards it's a 1" high tear and at 20 yards it's a bullethole.
 

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One other thing with the Duallys, they need to be shot from the wall. Be sure to pull through the shot. Since I don't paper tune, I have no idea how mine tears. The ruined arrows from group tuning indicate mine are tuned well. I start at 3/4" from the riser to the center of the arrow & 1/8" high. Tune from there.
 
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